Selector switch



May 30, 1933. F, MERK 1,912,087

SELECTOR SWITCH Filed April 50, 1932 2 Sheets-Sheet l 531./ f7; fa '593A @.30

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Filed April 30, 1952 2 Sheets-Sheet 2 FR/EDR/CH MERK www Patented May 30, 1933 UNITED STATES PATENT OFFICE FIEDERICH MERK, OF FRANKFORTONTHEMAIN, GERMANY ASSIGNOR TO H. FULD @c CO., TELEPHON- UND TELEGRAPHENWERKE AKTIENGESELLSCHAFT, F FRANK- FORTON-THEMAIN, GERMANY, A CORPORATION OF GERMANY SELECTOR SWITCH Application led April 30, 1932, Serial No. 608,541, and in Germany May 2, 1931.

The present invention relates to actuating members for bar selectors having a number of sets of brushes, each of which is held in an inoperative position by a locking member and of which one after a suitable movement of the actuating member relatively to a push rod is alone released by an action of the push rod applied to its locking member for making contact with the contacts of a section of the contact field. Such actuating members are known, for example, from U. S. Patent No. 1,712,393 granted to F. Merk, May 7, 1929. They have the advantage that the release of the selected set of brushes is effected suddenly Vby its own tensioning force, without a separate movement of the actuating member being necessary for this purpose, as is for example the case with bar selectors, of the Western Electric Company. Each movement of the actuatingmember is in this case purely a setting movement, firstly for selecting the desired set et brushes, and secondly for setting the set of brushes, rendered operative, on the desired contact of the contact field. An additional movement of the actuating member for rendering the selected setof brushes operative is not necessary so that the selector is particularly suitable for setting by number current impulses.

The construction of the actuating member described in U. S. Patent No. 1,712,393, however, possesses constructional defects which it is the object of the present invention to eliminate. In this known construction there isv used kas locking member a spreading spring mounted transversely in the middle of the set of brushes between the brush springs. Consequently the impulse members of the push rod and the strip portions, which produce a renewed return of the set of brushes when moved too far, are arranged in the middle of the contactfield. This arrangement is disadvantageous for the construction of the contact field and the formation of the set of brushes. Consequently separate brush springs must be relatively supported and, therefore, provided with insulating pads which easily leads to irregulai-ities when making contact.

In order to eliminate these disadvantages there isprovided in accordance with the present invention for each set of brushes a movable supporting member, on which all the brush springs are mounted, and a locking'meniber which holds the brush springs in theinoperative position by means of the supporting member and which by a temporai-y action of the push rod effects the release of the set of brushes, which latter thereupon under the action of a spring force acting on the supporting member, for example by the brush springs themselves, moves into the position necessary for making contact.

By the provision of a separate movable supporting member, which is independent of the locking member, the accessories of the sets of brushes are increased, but the construction and arrangement of the actuating members is considerably facilitated.

The advantages of the invention will appeal1 from the description of the drawings showing an example of construction in accordance with the present invention.

In the accompanying drawings Figure 1 shows a front elevation of an actuating member with five similar sets of brushes.

Figure 2 shows a section of the actuating member on the line A-B of Figure l.

Figure 3a shows a side elevation of the actuating member together with a push-bar and the contact field.

Figures 3b and 30 show the same actuating member in other positions'relatively to the push-bar.

Figure 4 shows a separate set of brushes erspective.

igure 5 shows in section a disengaged andv engaged set of brushes.

Figure 6 shows an actuating member with a larger number of different sets of brushes.

As carrier for the actuating member parts there is used a long base plate 11, consisting for example of sheet iron, strengthened by two ribs 30. The base late is mounted with its flat side in front o the fiat contact field and at a short distance therefrom (Figure 1) is movable up and down in the manner of a slide in guide members 12. f A projecizo tion 13 projecting forwardly at the bottom of the base plate effects the coupling of the actuating member with actuating mechanism (not shown).

The actuating member part-s, together with accessories, are provided on the front side of the base plate between the two strengthening ribs. The main space on the base plate is taken up by the sets of brushes 11 with the supporting members 15 located behind them. On the left hand side of the sets of brushes are provided the locking members Jormed as double armed levers 16; on the oppositely disposed (right hand) side a. cable 17 with the supply leads for the set-s ot brushes leads to ay terminal bar provided at the bottom of the plate.

The construction ot' the sets of brushes is shown in Figure 1. A bearing member 18, consist-ing ot sheet metal, and a support-ing member 15, hinged thereto and also consist# ing of' sheet metal and formed as a {ia-p, form the support for each set of brushes. On the bearing member is located an insulating block 19 with grooves for the reception et the brush springs 2O and soldering eyes. Over the springs is fitted an insulating and covering plate. These parts after assembling are first secured by the middle screw of the three screws 21 to the bearing inember 1S and thus form with the supporting member 15 ninged thereto a structural unit. Before applying this unit to the base plate 11, indicated in broken lines in Figure 4, there is fitted between the brush springs and the supporting member, extending over the entire length of the set o brushes to near the bent end of the brush springs, a thin insulating plate 22 so as to prevent the springs trom coming into contact with the supporting member. rlwo longitudinal ribs 31 provided on the insulating plate prevent lateral movement thereof. The set of brushes thus completed is now secured by means of the two outer sciews 21 to the base plate 11. After being secured in position, the brush springs, which have been pretensioned and bear against the supporting member 15, press the latter against the base plate, Whilst the free ends of the brush springs project freely into openings 23 in the base plate.

The supporting member 15 is provided with two diierently shaped projections 24 and 25 (Figures 4 and 5) for d isengaging or locking the disengaged sets of brushes. A set of brushes is disengaged when it sumes the position shown at the top of Fig ure it is engaged when it is located in the position shown at the bottom of Figure 5. The projection 25 co-operates with the locking lever 16. The upper end ot the lever, rotatable about a screw, constantly tends, by reason of a spring, to come under the projection 25 as soon as the supporting member is disengaged.V The disengagement takes place when during the movement of the actuating member t-he projection 24 of an engaged set of brushes passes over a roller 26 (Figures 2 and 3a) provided adjacent the contact field. The locking lever 16 in this case immediately moves in front oi the raised projection and locks the set of brushes until the locking lever is again disengaged.

For further explanation of the mechanical actuation of the sets of brushes reference will be made to Figures Lola- 3o. The contact eld shown in Figure 3a is a cross section of a known fiat bank multiple with ten contact groups l', 2 10, arranged in pairs. The sweeping of these contact groups takes place in the direction from the top downwards with only ivc sits of brushes which may be engaged selectively for the paired group 1 and 6', 2 and 7 and so forth. The points at which the sets otl brushes are moved into the engaging position before reaching the Contact groups is equal to the distance between the separate lines oi con tacts'ot the groups of contacts, this distance being hereinafter referred to as a contact step.

At the corresponding points on the contact field there is provided an insulating bar 27 against which the brush springs bear during engagement. This is to prevent the springs making premature contact with the iirst contacts, with which they are only to make Contact on the next actuating step or movement of the actuating member. The disengaging positions of the sets of lirushes are underneath the last contacts of each paired Contact group and are marked by the rollers 26 which are arranged laterally of some of the 1'nsulating bars 27 (Figin'e 2).

A rod 2S rotatably mounted adjacent the actuating member is provided with impulse fingers 29, the number of which coi-responds with the number of contact groups and which have the same spacing apart as the contact groups. On the actuating member, however, the spacing between the sets of brushes and locking levers corresponds with the distance between two consecutive paired contact groups minus an actuating step. Consequently, according to Figure 3a which shows the actuating member in the position of rest, distances an, a1 are j'giroduced which increase from the top downwards bctween the impulse ngers and the position 32 at which they engage with the locking levers. The distance corresponds with an actuating step. the distance with two actuating steps and so forth.

Assuming that it desired to obtain connection in the contact group fi, then the actuating member must be lowered four st ips. `When this has been done the actuating member according to Figure 3?) is in the position in which the seventh impulse lngcr from the top is just opposite the engaging positiony 32 of the locking lever belonging to the fourth set of brushes. By a slight rotation of the rod 28 the locking lever of the fourth set of brushes from the top, is now rocked into the position shown in Figure l and in this manner the corresponding set of brushes is released. This set of brushes on the further downward movement of actuating member can, therefore, sweep over the contact group fl.

If now it is desired to effect a connection in the Contact group 9 the actuating member is first moved downwardly 9 actuating steps, and then through 5 additional actuating steps. Wvhen this has been done the actuating member according to Figure 30 is in the position in which the eighth impulse finger from the top is just opposite the engaging position 32 of the locking lever corresponding to the same set of brushesvas before. By a slight turning of the impulse rod the set of brushes this time is disengaged at the beginning of the contact group 9. The above mentioned additional movement takes place in all selections above the numeral 5 and always amounts to five actuating steps.

At the end of a connection the actuating member, before being moved forwardly into the commencing position, is always lowered such a distance that its supporting member 15 passes over the next succeeding roller 26 whilst the supporting member, together with its brush springs, is raised and is held in the disengaged position by means of the locking lever which immediately comes in front thereof.

The example of construction of the invention above described clearly shows the utility which is obtained by the provision of a separate supporting member for the brush springs of each set of brushes and which is movable by a locking member adapted to be actuated by the push rod. It is now possible to arrange the engaging positions of the push rod and of the strip members on the actuating member laterally of the sets of brushes instead of in the middle thereof. The engaging positions are thus visible and accessible without interfering with the exchangeability of the actuating member. It is unnecessary to leave any room for the engaging positions in the contact field between the contacts of the separate sections, so that the height of the selectors may be reduced. The push rod may be provided with a number of push lingers for the separate sets of brushes, so as to enable these to be used for a number of contact field sections. The push rod may also be provided with push fingers for simultaneously engaging anumber of sets of brushes. f

The uniform mounting of all the brush springs of the brush set on a supporting mounted laterally of the sets of brushes, may

be in the form of metal pivoted levers. In this manner there is obtained a greater accuracy of their action by the push fingers of the push rod. The correct position of the locking members and of the push fingers is f of considerable importance for the operation of the selector as in every position of the actuating member, the positions only differ from 'one another by the movement of the actuating member through a few millime ters, the locking members of predetermined sets of brushes are capable of being actuated by fire determined push fingers of the push rod.

claim l. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a contact field divided into sections and a push rod, said push rod being provided with impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, a support member for retaining said brush springs in an inoperative position, means for moving said support member and a locking member for locking said support member, operable by a temporary movement of said push rod, for releasing the brush springs of a set of brushes by (3o-operation with said support member for moving into the operative position for making Contact with the contacts of said contact field.

2. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a contact lield divided into sections and a push rod, said push rod being provided withV impulse members for operating one of said sets of brushes after a cor responding movement of said brush support, each of said sets of brushes containing a plurality of brush springs adapted to store up a pressure force, a supportmember for retaining said brush springs in an inoperative position and moved by the pressure force stored up in said brush springs, and a locking member for locking said support member, operable by a temporary movement of said push rod for releasing the brush springs of a set of brushes by co-operation with said support member for moving into the operative position for making Contact with the contacts of said contact field.

3. A movable brush support, supporting a plurality of sets'of brushes for a selector,

im ytive pt,

saro sets ot responding movement ot' said brush support, each of said sets et brushes Containing a 1"ility of brush springs adapted to store port member for il lilOpQlare torce stored up in sa' '.ush sprin member K movementof said support membri; said locking member being' operabie bv a temporary movement o said push f l releasing said support 'm on said support member i o the contact path a strip mer eaeh section ot said Contact fiel( oit movement of said projee' s ilor moving said locking me aid means bei mrt meniber `ing upon l'. i brush support, supporting 5 sets ot brushes for selector, a Contact iieid divided into scctions and a push rod, said push rod being provided with impu .te members 1for operating one ot said s of brusin-is ter a corrtspondingf; movement ot said brush support, each ot' said sets of brushes coi'itaining a plurality of brush springs adapted to store up a pressure for e, a support member for retaining said brush sprines in an inoperative j; 'tion and moved by the pressure torce stored up in said brush springs, a locking member tor pre venting movement of said support member; said looking member being operable by a temporary movement of said push rod for releasing said support member, a projection on said support member projecting into the Contact path, and arranged iaterally oi said brush springs, a strip member behind each section of said Contact "eid in the path of movement of the proj Aon of said support member, arr red lateraily of the contact blades ot salu, Contact held, and means for moving said locking; member into the lockingT position; said means bei K operative a said supportmember is raised by its projection st ing upon said strip member.

5. A movabie brush support, supporting a plurality of sets of brg for a selector. comprising a Contact field divided into sec tions and a push rod, said push rod being' provided With impulse members tor operan ing one of said sets oit. brushes a ter a corresponding movement ot' brush support, each of said` sets of brnshes containing a springs. means Yfor clampj Y support member, for retaining said brush springs in an inoperative position, consisting ot stationary plate, a shaft and a plate movable about said shaft, means for securing the clamping means of said brush springs upon the stationary plate of said support member, means for securing said stationary plate together with said brush springs to said brush support and a locking member for preventing movement of said support member, said iocls ing member being operable by a temporary movement of said push rod tor releasing said support member, a projection on said support member projecting into the Contact path, a strip member behind each section of said contact ield in the path ot movement of said projection, means for moving said locking member into the locking position, said means being operative soon as said support member is raised by its projection striking upon said strip member.

6. movable brush support, supporting a plurality of sets of brushes for ar selector, comprising a contact field divided into sections and a push rod, said push rod being provided with impulse members tor operating one ot' said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, means for clamping said brush springs, a support member, ior retaining said brush springs in an inoperative position, consisting o i a stationary plate, a shaft and a plate movable about said shaft, means for securing the clamping means of said brush springs upon the stationary plate of said support member, near the shaft of' said support member.

7. A movable brush support, supporting a plu 1ality oi sets ot brushes for a lector, comprising a Contact field divided into sections and a push rod, said push rod being provided with impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, means jior ciamping said brush springs, a support member, for retaining said brush springs in an inoperative position consisting of a stationary plate, a shaft and a plate movabie about said shaft, means for securing the Clamping means of said brush springs upon the stationary plate of said support member, near the shaft of said support member, an insuiated intermediate layer betvfeen ihn movable plate of said support member and said brush springs.

8. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a Contact held divided into rections and a push rod, said push rod being provided with impulse members for operating one of said sets oi.E brushes r a corresponding movement of said brush support, each of said sets of brusl containing a piurality of brush springs, means for clamping said brush springs, a support member, for retaining said brush sprin s in an inoperative position, consisting o a stationary plate, a shaft' and a plate movable about said shaft, means for securing the clamping means of said brush springs upon the stationary plate o'lf said support member, means for securing said stationary plate together with said brush springs to said brush support and a locking member for preventing movement of said support member, said locking member consisting of a two-armed lever mounted on a shaft on said brush support, a spring, pressing one arm of said locking member under said support membei', the other arm operable by a temporaryr movement of said push rod for releasing said support member, a projection on said support member projecting into the contact path, a strip member behind each section of said Contact ield in the path of movement of said projection, means for moving said locking member into the locking position, said means being operative as soon as said support member is raised by its projection striking upon said strip member.

9. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a Contact field divided into sections and a push rod, said push rod being provided with impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, means for clamping said brush springs, a support member, for retaining said brush springs in an inoperative position, consisting of a stationary plate, a shaft and a plate movable about said shaft, means for securing the clamping means of said brush springs upon the stationary plate of said support member, means for securing said stationary plate together With said brush springs to said brush supr port and a locking member for preventing movement of said support member, said locking member consisting of a two-armed lever mounted on a shaft on said brush support, laterally of one of each set of brushes.

l0. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a Contact lield divided into sections and a push rod, said push rod being provided With impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing av plurality of brush springs, a support member for retaining said brush springs in an inoperative position, a stored force for moving said support member and a locking meniber for preventing movement of said support member, arranged upon said brush support laterally of said brush springs, said locking member being operable by a tembrush springs, a strip member behind each section of said contact field in the path of movement of the projection of said support member, means for moving said locking member into the locking position, said means operating as soon as said support member is raised its yprojection striking said strip member and supply leads to the brush springs of the different brush sets arranged upon said brush support adjacent said brush springs on the side thereof remote from said locking members.

ll. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a contact field divided into sections and a push rod, said push rod being provided with impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, a support member for retaining said brush springs iii an inoperative position, means for moving said support member and a locking member for locking said support member, operable by a temporary movement of said push rod, for releasingr the brush springs of a set of brushes by co-operation with said support member for moving into the operative pof sition for making contact with the contacts of said contact lield, a greater number of impulse members on said push rod than sets of brushes on said brush support, said impulse members arranged in such a manner that after a corresponding displacement of said brush support, the locking member of one set of brushes is located in front of a corresponding impulse member and another displacement of this locking member in front of another corresponding impulse member of said push rod.

12. A movable brush support, supporting a plurality of sets of brushes for a selector, comprising a contact field divided into sec tions and a push rod, said push rod being provided With impulse members for operating one of said sets of brushes after a corresponding movement of said brush support, each of said sets of brushes containing a plurality of brush springs, a support member for retaining said brush springs in an inoperative position, means for moving said support member and a locking member for locking said support member, operable by a temporary movement of said push rod, for releasing the brush springs of a set of brushes by co-operation With said support member for moving into the operative position for making contact vvith the contacts of said contact field, the impulse member of said push rod being arranged in such a manner that after a displacement of said brush support7 the locking members of two associa-V ted sets of brushes` are simultaneously lo'- cated in front of two impulse members of said push rod.

13. A movable brush support, supporting a plurality of sets of brushes for a selector, Comprising a Contact field divided into sections and a push rodt impulse members on said push rod, said impulse members consisting of pins screwed into said push rod for operating one of said sets of brushes after a correspondixig movement of said brush support, each of said sets of brushes containing a plurality of brush springs, a

support member for retaining said brush sprines in an inoperative position7 means for moving said support member and a locking member for locking said support member, said locking member being operable by a temporary movement ot' said bush rod for releasing the brush springs o a set of brushes by cooperation with said support member for moving into the operative position for making Contact with the contacts of said Contact iield.

In testimony whereof I affix my signature.

FRIEDRICH MERK. 

